The present invention relates to a distributor of a fluid under a pressure which is a function of the pressure of a control fluid. Such a distributor is used particularly in systems amplifying a manual control, such as a hydraulic actuator employed, for example, for boosting the clutch control on a motor vehicle.
Such a bifluidic distributor is described, for example, in EP-A-0,310,733.
This distributor of a fluid coming from a source of fluid under a first pressure and under a pressure which is a function of the pressure of a control fluid comprises, in a bore made in a body, a double valve means consisting, on the one hand, of a first piston, one end of which defines with a first plug a control chamber receiving the control fluid, while the other end is pierced with a conduit connected to a source of fluid under a second pressure, an annular chamber surrounding the first piston and being connected to the consumer circuit of the distributed fluid, and, on the other hand, of a disk forming a shutter and resting by means of a return spring on a circular seat stationary relative to the body, the disk being opposite this other end of the first piston, this other end being capable, under the action of the pressure prevailing in the control chamber, of coming up against the disk so as to close communication between the conduit and the annular chamber and then of displacing the disk so as to open communication between a conduit for the inlet of the fluid under the first pressure and the annular chamber.
Such a distributor, which, in the document mentioned, was designed particularly for supplying a compressed gas, has a disadvantage of supplying this gas only from a high value of the pressure of the fluid in the control chamber, determined by the pressure of the gas in the source of the inlet of the distributor. This gas in the source of the inlet of the distributor. This threshold or jump is not always desirable in practice.